What is the most statistically significant 95% confidence interval for a study measuring the risk of melanoma associated with tanning bed use?

The correct answer highlights a range that indicates a statistically significant association between tanning bed use and the risk of melanoma. A 95% confidence interval that does not cross one suggests a significant relationship, as it implies that the risk is greater than the baseline without the exposure.

In this case, the interval from 1.2 to 1.7 indicates that we can be 95% confident that the true risk associated with tanning bed use lies within this range. This suggests that tanning bed use is associated with an increased risk of developing melanoma, as all values in this interval are above 1.

The other intervals do not demonstrate a significant increase in risk. For instance, an interval that spans from -0.9 to 0.9 includes 1 and contains negative values, which would suggest no association or even a potential protective effect. An interval such as 0.9 to 1.7 is close to but does not clearly show significant elevation in risk, as it is still very close to 1. Thus, the lack of clarity in separation from a null effect makes it less convincing statistically.

Intervals like 1.01 to 1.73 show statistical significance but are not as strong as the 1.2 to